Weeds are prolific in the summer when the warm weather and rainfall provide ideal conditions for growth and seed germination. Common weeds, including dandelions, daisies, bindweed and ground elder, are easy to spot with their distinctive leaves and flowers, but it also means they are hard to ignore.
For those who avoid chemical weed killers, white vinegar, baking soda, salt and hot water are common remedies suggested for the job, though they do not solve some of the harder bits of weed removal like the pulling and spraying.
A gardening expert has suggested a hands-free defence against weeds known as “sheet mulching.” While professional landscapers have adopted this practice for years, it’s a “revelation” for the average home gardener looking to maintain beds and borders.
Elizabeth Florio of Garden & Gun said: “It turns out the cardboard that passes through… households in abundance is a low-fuss, good-for-the-soil, sustainable-many-times-over weed barrier.”
The method is simple: lay a flattened cardboard box over clusters of weeds and top with garden mulch.
According to the gardening maestro, this works by “smothering the undergrowth” while simultaneously enriching the soil with carbon.
It’s a worthwhile option for gardeners who take a no-dig approach to unwanted growth, and one many people have successfully put into practice.
A gardening enthusiast shared on the Charles Dowding forum that they found cardboard to be an “amazing” remedy for suppressing all kinds of garden weeds.
The forum member revealed: “Under hedges I put cardboard with wood chip on top, nothing through at all.”
They continued: “We also had a weed-ridden border which I put cardboard first, then planted heather into holes cut in it, then put peat compost all over as mulch and it is doing well, heather alive and had to pull about two weeds in two months.”
How to kill weeds with cardboard
This method is best used on areas of thick weeds like grass with big dandelions.
There’s no need to pull existing weeds before laying cardboard on top. In fact, many Charles Dowding forum members suggest that doing so just encourages more weeds to grow.
Instead, they recommend cutting them down and, if you wish, letting the top layers flatten them.
Certain types of cardboard are best for use in the garden, and gardeners should opt for the plain brown kind.
Use sheets with minimal ink and avoid glossy materials, which can contain plastic film or wax. The same goes for cutoffs with tape on them, which is why pizza boxes are generally the safest bet.
Elizabeth suggests layering flattened boxes for maximum hold against weeds. Hosing them down with water is also recommended to ensure the cardboard conforms to the ground and stays put.
If you’re topping the cardboard layer with new plants, you will need a layer of compost and planting soil. Just spread your mulch — be it wood chips, pine straw, or other organic materials — directly on the cardboard.
